Online Geology Course

Here is a “how” series on ore mineral deposit formation acting as a FREE Online Exploration Geology Courses to help non-technical people understand ore deposits, how they form, how they are explode for, how they are evaluated and mined and how the metals and minerals are extracted from the ore. The talks highlights some of the features of the main ore deposit types that you may come across and provide an introduction to the vocabulary that use by exploration and mining companies.

You can also read these totally great paper and listed here:

I took this from a series of great exploration geology articles located at explonationinsights.com

Here a the series in this ore deposits Exploration Geology Course series. Each talk covers one or more of the major ore deposit types.

This first guide is more of an introduction and it covers plate tectonics and the fundamental role that a plate tectonics plays in the formation of many ore deposit types. The geology course will cover various ore forming processes concentrating particularly on those associated with the cooling and crystallization of magma as they rise through the earth’s crust. Here we point out that because of our limitations in current mining technology (Hard Rock-Mining-Engineering-Handbook) all metals and minerals that we use are mined from the earth’s crust. We also noted that the average abundance of metals in the crust wasn’t high enough for economic mining and that nature needed to provide a significant concentration of the metals and minerals in order to make grades which can be economically mined. Describing the process of partially melting rocks to concentrate metals into the melt portion and bringing that melt up through the crust to a shallower depth where it can be mined while cooling it to allow valueless minerals to crystallize out and be left behind and the remaining melt to be enriched in metals. I also mentioned that certain minerals that we do want sometimes crystallize or separates out early in this cooling process. These include chromium, platinum, copper, nickel, and diamonds and today I’m going to talk about these metals and minerals are starting with the copper nickel sulfide deposits and then the platinum chromium deposits and ending up with diamonds and for each of these you will learn about; how the deposits formed, Some of the better-known examples of each of these deposit types and how you explore for them.
How are Ore Mineral Deposits Formed series will focus on deposits associated with mafic layered complexes such as nickel, the platinum group metals and igneous rocks. The best known of these layered intrusions of the Bushnell complex in South Africa. Included in this free online geology course is a section about kimberlites and their associated diamond deposits and learn that diamonds originate in kimberlite pipes or dykes including those in placid deposits. Kimberlite is an ultramafic rock derived from the mantle. Diamonds crystallize in the mantle well below the crust but they are carried up into the crust by the rising kimberlitic magma.
This will focus on exploration for porphyries deposits, those massive but low grade deposits of copper, molybdenum and gold that roam the Pacific Ocean. We’ll also briefly discuss iron oxide copper gold deposits IOCG in this talks such as the Giant Olympic Dam deposit in South Australia. Included in a short copper extraction process description. Porphyries and IOCG’s are generally very large but low grade. Skarns do not necessarily have the same characteristics. Porphyries and IOCG’s are generally fairly homogenous in grade. There may be some zoning and variation of metal ratios but over tens of meters grade tends to be pretty consistent. Skarns again do not fit this pattern and they can vary considerably in grade just over a few meters. Once you’ve see a few porphyries you’ve seen them all. The reverse is true of IOCG’s so that deposits at each end of the spectrum of iron oxide copper gold deposits IOCG can be totally unrecognizable as belonging to the same group of deposits. Porphyries, skarns and IOCG deposits very often have both oxidized and unoxidized portions. This is important as it impacts on capital costs. Capital cost for building up porphyries and IOCG mines are generally high compared to other deposit types. This is due to the combination of multiple ore streams and the huge size and tonnage needed. Geophysics plays a crucial role in exploration for each of these deposits.
This course will deal with vein deposits that formed deep in the crust and host gold and copper. Most prolific of these are those found in the ancient greenstone belt which provide a significant proportion of the world’s gold production. Orogeny refers to forces and events leading to a large structural deformation of the Earth’s lithosphere (crust and uppermost mantle) due to the interaction between tectonic plates. Vein deposits form from hydrothermal fluids rising through earth’s crust toward its surface. These fluids, commonly created by magma moving through the earth’s crust, travel the path of least resistance through fractures and faults in the rock. There are two basic types of vein deposits you can explore for: epithermal and mesothermal deposits.
Covers the so-called epithermal deposits geology. These are formed at shallow depths and are host to gold deposits and silver and sometimes lead and zinc as well. The Yanacocha deposit in Peru which had reserves a 32 million ounces in 2005 belongs to this group of deposits. High sulphidation epithermal deposits compared to low sulphidation epithermal deposits marks the ores for exploration.
How are Ore Mineral Deposits Formed will be dedicated to Carlin gold deposits and how to explore for . Carlin Type Gold System. Carlin deposits are very attracted to major mining companies as they can be very big and they are often high-grade as well they are indeed big elephants. They are hosted in dirty limestones in Nevada, this means mainly in the lower plate rocks and associated with long-lived crustal scale faults. The gold itself is to fine to see with the naked eye or to pan; the so-called micron gold.
Addresses the Volcanogenic Massive Sulphides or VMS deposits as well as Sedimentary Exhalative Ore Deposits which are formed by hot springs on the seafloor and are a major copper, lead, zinc and gold producers. When comparing VMS and SEDEX deposits, you understand the differences.
Covers the Witwatersrand gold deposits in South Africa, the biggest source of gold on earth. The Witwatersrand Gold Deposits are biggest elephants of all in the world of giant’s gold ore deposits. The Witwatersrand gold deposits. It thought it might be interesting to start of today’s talk with a bit of history and run through the events that led up to the discovery of the Witwatersrand gold fields. Except for a fluke of nature these large gold deposits might never have been discovered even as there are claims to be the biggest elephants of all. The greatest controversies in the geological world; the genesis of the Witwatersrand Gold ore deposits. There are two main competing theories of origin and then offer a third possibility. Review a short section on how these remarkable deposits are mined and the technical and social issues involved which will lead us onto the last section; what is the future of the Witwatersrand gold industry.
How are Ore Mineral Deposits Formed will deal with the most common types of Uranium deposits and the last two don’t deal with specific ore deposit types, Instead they deal with exploration and the evaluation of deposits. Uranium is not rare and it incurs in most rocks. It’s just a question of finding the rocks with higher and more consistent grades. Deposits can be split into primary deposits those within the original igneous source rock and secondary deposits where the uranium has been leached by groundwater and concentrated somewhere else.
The exploration process; what exploration tools are available and how the exploration geologists selects which ones to use. It also talks about exploration strategies.
The final post in the Exploration Geology Course series on How are Ore Mineral Deposits Formed deals with ore resources and reserves and once the mineral deposit is discovered, the process that is taken to evaluate it and reach a go or no go decision to mine. Ore resources and reserves and deal with how resources and reserves are delineated and projects evaluated so that we can reach the decision to either build a mine or abandon the project.

More great FREE Geology Courses:

Syllabus—Description, procedures, and objectives of the course
Schedule—Links to weekly agendas, lectures, and lab assignments
Grading Rubrics—Standards for assessments in the course
Basics—Explanations of basic concepts in geology
Basics Tables—Summary tables of basic geologic information
Focus Pages—Essential elements of the geology of the Pacific Northwest
Lectures—Course lectures
Virtual Field Sites—Selected geological field sites in the Pacific Northwest
Glossary—Definitions of geological terms used in the course

All the Elements of Geology